Converting 1.94 heads to 2.02 heads correctly
 

I am putting my 69 Z back to 100% (or as close as I can get) original.

I have the original block, but the heads were long gone. PO put some angle plug heads on it. I have some very nice correctly dated 186 heads, but they have the 1.94 / 1.50 valves in them.
I need them converted to run 2.02 / 1.60 valves.... correctly. I know there are guys out there doing chitty jobs on stuff like this, and I want these done right.

Getting really hard to find a competent machine shop locally. We had three here in OKC area 20 years ago that did outstanding work. All closed.

Already have a couple of feelers out to individuals whom I have great respect for. Just wanting to know what my options are.

Who can I get to do this correctly?

On a completely different subject; I heard Manley has moved production of their valves off shore (i.e. China). Supposedly the high end pistons are still made in USA. I realize it is possible for quality parts to be made overseas as long as the quality control is there from start to finish. Anyone have issues with Manley valves made overseas?
If so, what are you guys using for valves on street cars?

Thanks for any suggestions.

You could have them shipped to Total Flow in Troy, MI - they are the only shop I use for this kind of work in the Detroit area. Regarding the valves, have you looked into Ferrea instead?

Ferrea seems to be the consensus winner; at least in on line conversations.

2.02/1.60 Conversion..
 

Lynn...

I have a great machine shop in NY that could likely help...he does all our work.

First rate guy and excellent results. Just sent him a note about your project.

I assume you want to add the screw in rocker studs as well?? Do you want any other enhancements.??

Of course you would have to ship the heads...

Happy New Year...Tom

Also make sure whoever does it does the unshroud cuts on the intake valve area in the combustion chamber. Most anybody competent will know to do this, but don't underestimate anybody these days. I did and got screwed.

These guys are very good:

https://www.headsupcylinderheads.com/services2.html

Pin the studs at least for the stock look and peace of mind.

Exhaust manifolds or headers Lynn?

Tim:
Exhaust manifolds on this one. I do have a really nice set of headers from a small company that went out of business in 2009 on the car right now running an L46 (HW code) converted to LT-1 specs. Magnaflow system from the headers back.

I suppose it is POSSIBLE that I change my mind again after putting the 302 in and running stock manifolds and stock exhaust. I doubt it.

At least for NOW, planning original manifolds, gutted smog pump, with all the smog pieces in place and stock exhaust, meaning two resonators and the transverse muffler. I have all the original hangers for my car and all NOS exhaust from the mid 70s.

"...make sure whoever does it does the unshroud cuts on the intake valve area in the combustion chamber."
Dave; that is part of what I meant by doing it correctly. They need to LOOK exactly like factory 2.02 heads when done.

Not concerned with converting to screw in studs. Z/28 did not have screw in studs in 1969. While I might drive it a little hard occasionally (I do now) I don't see living at 7,000 rpm. Doubt I will ever pull a stud. Could always pin them. Did a bunch that way back in the day.

I already have a pair of 186 heads fully ported, screw in studs, true 2.02 heads ready to bolt on. Would be a waste on a car with manifolds. Have not even checked the dates, but not likely a match for my block, or I wouldn't have had all that work done to them.

Sorry for the long response.

FWIW, I don't think it makes a difference on a car with manifolds. Buying good valves and a good valve job should be to be MORE than ample without enduring the additional expense.

Of course, that is strictly my opinion. I've never found my opinions to be in high demand.:wink:

Speaking of useless opinions, I'm wondering why bother having the heads opened up to correct size valves when it will be breathing thru manifolds and not driven hard. No one, but you, will ever know they are the small valves unless they look with a scope. Pulling a valve cover and verifying correct cast date will be about as far as any, normal, person would go on an inspection.

Don't consider EITHER of you guys' opinions useless.

Mitch; I know in my heart you are correct about the 1.94s. I have argued for years that on most street cars (especially with cubes down at the 302 level) they would be more responsive down low with the 1.94 valves. Just to play devil's advocate. Two things: 1. This car has almost no repop parts. It still retains the original MC and booster, as well as 99% of the sheet metal. Original engine block, original trans and maybe the original rear (long story on that). I may be the only one who will know, but I will always know that I wimped out on one of the most well known components of the Z/28 302 engine.
Secondly, I doubt I will be selling those S&S headers. What if I get a wild hair one week and decide to put on the open headers, install the 4.88 gears and see what she will do? Likely? No. Possible. Yes. I change my mind almost as often as I change socks.

I just want it as right as I can make it.

Thanks for the suggestions and the leads. I also have a lead on an older gentleman local to me who may be quite capable of doing this correctly. Plan to visit with him towards the end of next week.